Noise absorption and insulation materials have been installed in the interior of a vehicle, so as to block engine noise, remove dust and absorb noise, and to prevent transmission of low frequency and high frequency complex energy generated during driving to the interior space of the vehicle.
However, in the case of such conventional noise absorption and insulation materials for a vehicle, a separate noise insulation material is adhered to a surface material layer and a noise absorption material constituting the noise absorption and insulation material by using an adhesive, or direct coating, and the like. Accordingly, there are problems of decrease of vehicle fuel efficiency due to an increase in the overall weight of the noise absorption and insulation material, as well as decrease of productivity due to the complicated production process of the noise absorption and insulation material.
On the other hand, polyester, which is often used as a noise absorption material for improving noise absorption performance, has weak organization due to the structural characteristic of having noise absorption performance and the like, and therefore there are problems in which wear-resistance is weak, it is easily damaged by flooding, brittle resistance at low temperature is weak, its surface layer is easily contaminated and damaged, and its appearance becomes poor.
No particular suggestions for solving these problems have been found in the prior art. However, in regard to techniques about general noise absorption and insulation materials, Korean Patent Publication No. 1181201 discloses a method for manufacturing a wheel guard for vehicle, which comprises: a first felt layer forming step of forming a felt layer by carding polyester fiber and needle punching thereof; and a second felt layer forming step of forming a felt layer by carding polyester fiber and needle punching thereof, but it is not considered to be excellent in constitution of noise absorption and insulation material, and in noise insulation performance.
Further, Japanese Patent Laid-Open Publication No. 2011-143763 discloses an automobile exterior material comprising a thermoplastic resin layer on one side of a non-woven fabric layer, in which a molten thermoplastic resin sheet extruded from an extrusion molding machine is formed by pressing a laminate laminated on one side of the non-woven fabric in the thickness direction, but the constitution of the noise absorption and insulation material and the noise absorption performance are not excellent.
Further, Korean Patent Publication No. 768824 discloses equipment for production of a functional multilayer extruded sheet, in which a non-woven fabric or textile supplements made of natural and plastic fibers, as a material of part for a vehicle such as vehicle trunk part, wheel guard, door trim and rack, is formed as multi-layer inside or outside of the extruded sheet, but in view of the constitution of the noise absorption and insulation material used, air-permeability is not achieved.
In addition, Japanese Patent Laid-Open Publication No. 2008-087695 discloses an automotive sound insulation/water-proofing type mud guard, in which a water-proofing membrane is formed by impregnating a foamed acrylic based/SBR based resin of 50 g/m2 to 500 g/m2 on a back side of a non-woven fabric layer having impact absorbing and noise absorbing functions, but it can't have air-permeability in view of constitution of the noise absorption and insulation material, and it is not considered to be excellent in noise absorption performance and noise insulation performance.
Accordingly, fundamental efforts to solve interior noise problem by reducing noise generated from dynamic machines such as vehicles, and at the same time, to reduce weight and production cost and the like are needed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.